Looks like it crashed while scanning for new items for the library, and it did so just after the 203 folder in your Simpsons folder. There might be a funky file in there that confuses/freezes XBMC up. Try temp removing/moving that folder and maybe the one after it and see if a library scan will still freeze XBMC. If XBMC doesn't freeze that time then there is a weird file inside. Our devs would likely be interested at examining the file to see why this happens.